A three-dimensionally preserved aglaspidid euarthropod with a calcitic cuticle from the Ordovician of China

Abstract

AbstractAglaspidid euarthropods are usually preserved as flattened carapaces. We here describe a new species and genus,Gogglops ensifer, from the Ordovician Shaanxi Province, China, which shows the best three-dimensional (3D) preservation yet discovered. We show that the cuticle was originally composed of calcium carbonate, except for the visual surfaces of the eyes which were probably originally organic but have been selectively phosphatized. A review is given of the problems pertaining to the original nature of the aglaspidid cuticle.Gogglopsis probably closely related to certain poorly known aglaspidid genera from Ordovician deposits of the Siberian Platform. Phylogenetic analysis indicates that the new genus is closely related toAglaspisitself, and securely nested within the clade Aglaspidida.